I always took the word pop more literally to be of the in genre at the time, whatever that is.
Then there is the basic band with the beginning, middle and end along with mostly (but not always) 3 part harmony that is more of an offshoot of pop, however it comes out.
Even though it would be hard to look at some of those bands as pop.
Especially The Doors.
Pop is supposed to be such an unflattering term, but all pop is really is music that moved out of the countraculture. At least over the last 40 years.
There is stuff now that would have sounded pretty wild 20 years that is generalized as pop. Maybe even 10 years ago.
I just think of 2 basic musical categories, music or muzak.
Wherever that falls depends on ones tastes.